Barcode scanning technology has been widely used in warehouse management, cashier payment, etc., which helps to improve work efficiency and intelligent management. Based on the differences on code class, printing material and screen display medium of the one-dimensional bar code and the two-dimensional bar code, the bar code scanning device is mainly divided into an image type bar code scanner and a laser bar code scanner. Specifically, the scanning speed, scanning distance, scanning sensitivity of the laser bar code scanners are better than the image type bar code scanners.
Since the laser bar code scanning device is a single-line scanner, the number and the direction of the laser scanning lines are important factors affecting the bar code reading effect. Generally speaking, if the quantity and the direction of the scanning lines are more, the scanning effect of the device is better. In the prior art, the solution is to increase the direction and quantity of the laser scanning line by adding laser emitters and photosensitive receivers correspondingly matched with the laser emitters, thereby improving the bar code recognition effect. However, since the prior art adopts single channel with one laser emitter matching with one photosensitive receiver to recycle the laser beam, so as to proceed with photoelectric conversion decoding, thus the plurality of photosensitive receivers cannot work effectively at the same time, non-coaxial optical signal crosstalk will be generated among the photosensitive receivers. Further, the use of multiple photosensitive receivers leads to higher hardware costs.
In laser bar code scanning applications, high-resolution bar code recognition is mainly affected by the laser half-width and resolution. Low-resolution bar code recognition is mainly affected by laser spot intensity and depth of field, but a single laser source cannot balance spot resolution and depth of field. Therefore, a single laser emitter barcode scanner has a limitation that cannot simultaneously extend the high-resolution depth of field and low-resolution depth of field.